Two billionaire brothers who control Asia's biggest property development company have been charged with corruption, anti-bribery officials in Hong Kong said Friday.

Sun Hung Kai Properties (SHKP) co-chairmen Thomas and Raymond Kwok were among five people charged with a total of eight offenses, including conspiracy to offer advantages to a public servant and misconduct in public office, the Independent Commission Against Corruption (ICAC) said in a statement.

Hong Kong's former chief secretary Rafael Hui, banker Francis Kwan and Thomas Chan -- responsible for land acquisitions for SHKP -- were the other men charged after one of the biggest anti-graft probes in the banking hub's history.

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The case has caused a media frenzy in the city, where real estate is a local obsession. Sun Hung Kai, which helped to build some of the tallest buildings in the city's celebrated skyline, contributed to the Kwok brothers' estimated $18.3 billion fortune.

The brothers, who were arrested in March, have protested their innocence.

"I can say that personally I have done nothing wrong. And I can vouch for Mr. Thomas Kwok that he has done nothing wrong either," Raymond Kwok said at a news conference on April 3, referring to his brother.

"I hope this investigation will clear my name," he said.

Hong Kong, a special administrative region of China, is considered to be one of the world's least corrupt territories. According to Transparency International's 2011 Corruptions Perceptions Index, Hong Kong is the 12th least corrupt territory in the world -- with the United States, by comparison, ranked 24th.